小蘖碱的次氯酸钠比色测定法

小蘗碱对许多病原菌有抗菌作用,临床上广泛用于治疗细菌性痢疾,效果良好。关于小蘗碱的定量方法文献记载有重量法、容量法、电流滴定法、离子交換测定法、非水溶剂滴定法、极谱分析法、分光光度法等。彭煜南用硝酸比色法测定小蘗碱,操作仍较麻烦,需加热、恆温等手续。我国普遍采用苦味酸沉淀法测定小蘗碱及其制剂的含量,该法的缺点是专属性差,操作繁瑣,效率较低。远在1885年Hofmeister和Lenz曾指出,氯水加到盐酸小蘗碱水溶液中呈现红色反应,反应的灵敏度为10微克。作者用以下方法可使检出限量达1微克,限界稀度为

The Sodium Hypochlorite Method for the Photometric Determination of Berberine

In this paper, the visible absorption spectra of a red colour, produced by adding one drop of the solution of sodium hypochlorite (containing about 2.6 to 2.8 mg chlorine per 100 ml) to a solution of berberine hydrochloride in 8 N hydrochloric acid, were studied. The red colour is stable within 2 hours and a procedure is proposed as follows: Accurately pipette 0, 1, 2, 3, 4, 5 ml of the standard solution (equivalent to 0, 0.1, 0.2, 0.3, 0.4, 0.5 mg of anhydrous berberine hydrochloride) into 25 ml volumetric flasks respectively, add water to make 5 ml. Dilute the solution to about 20 ml with 10 N hydrochloric acid, mix well, allow to stand for 10 minutes, and determine the optical density at 510 mμ (first solution as blank). Accurately pipette 5 ml of sample solution (equivalent to 0.25 mg of berberine hydrochloride) into 25 ml volumetric flask and proceed as above. The colour intensity was found to obey Beer's law within the range of 0.1 to 0.5 mg of anhydrous berberine hydrochloride per 25 ml. The percentage of error of this method is -1.54 to +1.50%. The results of determinations of berberine hydrochloride tablet, berberine hydrochloride injection, and berberine citrate injection are in agreement with those obtained by the official method. This method may be applied to the determination of berberine in the presence of hydrastine with no interference.